• Journal of IKEEE
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• v.28 no.3
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• pp.329-336
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• 2024

Organic light emitting diode(OLED) is distributed in layers with different refractive index, which leads to total internal reflection and low light extraction efficiency. As a result, light extraction technologies have been investigated that include structures such as MLA. However, technologies such as MLA are using petroleum-based polymers, which cause environmental problems during disposal. Therefore, this study investigates the use of eco-friendly polymers hydroxyethyl cellulose(HEC) and tannic acid(TA) to produce external light extraction films. HEC is biodegradable and has high transparency, making it suitable for eco-friend external light extraction films. The TA used as an additive is a polyphenolic molecule, which is expected to form strong hydrogen bonds with HEC. In addition, TA can protect OLED from damage by UV light through its phenolic groups. HECTA MLA films were produced by dissolving HEC and TA in water without using additional solvents and then imprinting them on MLA mould. When the HECTA MLA film was attached to the outside of the OLED and analysed, it showed a high Haze of more than 80%, and the external quantum efficiency and current efficiency of the OLED were improved by 38% and 39%, respectively, compared to the reference.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.6
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• pp.3799-3804
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• 2014

In sea water, microalgae are exposed to a range of critical environmental conditions. Microalgae are protected from UV-A radiation due to the presence of mycosporine like amino acids(MAAs). Owing to the UV-A absorption properties of MAAs, they are used widely as a UV protecting ingredient in cosmetics. Therefore, there is a need to increase the production yield of MAAs. This study investigated the production yield of MAAs in transformed microalgae by radiofrequency(RF) exposure. Initially, the Glut-1 gene was transformed to Chlamydomonas hedleyi microalgae as a glucose transporter. The biomass was enhanced after Glut-1 gene transformation. In addition, the MAAs production yield was increased during large scale production in bioreactors due to the RF treatment. Therefore, purified extracts of MAAs can be used as a sun block material in the cosmetic industrial field.

• Journal of Mushroom
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• v.11 no.2
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• pp.99-106
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• 2013

This study was initiated to investigate the skin whitening activities of methanol extracts from fruiting bodies of I. obliquus. The total polyphenols and flavonoids contents of I. obliquus methanol extracts were 31.85 mg/g and 28.33 mg/g, respectively. The methanol extract of the mushroom treated on B16/F10 melanoma and NIH3T3 cell lines did not show cytotoxic activity. 2,2-diphenyl-1-picrylhydrazyl(DPPH) free radical scavenging activity and chelating activity on ferrous ions of I. obliquus methanol extract were lower than those of positive control, tocopherol and BHT. The tyrosinase and L-DOPA inhibitory activities of the extract were lower than those of positive control, kojic acid and ascorbic acid. The tyrosinase and melanin synthesis inhibitory activities of the melanoma cells treated with the extract were comparable with positive control, arbutin. The experimental results suggested that methanol extract of I. obliquus contained inhibitory activities of tyrosinase and melanin synthesis in the B16/F10 melanoma cells by dose dependent manner. High ultra-violet absorption spectra in the range of 280-350 nm showed that I. obliquus extract could protect skin from UV radiation damage. Therefore, fruiting bodies of I. obliquus can be used for developing skin whitening, anti-UV and skin care agents.

• Proceedings of the Korea Society of Costume Conference
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• 2001.04a
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• pp.50-51
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• 2001

많은 소비자들이 가치지향적인 의사결정을 할 때 제품의 품질을 매우 중요한 요소로 생각하며, 제품구매시 불완전한 정보 상황에서 빈번히 제품품질의 지표로서 가격을 이용한다고 한다(Peterson & Wilson. 1985). 이와 관련하여 시장에서의 실제 가격과 객관적 품질과의 관계를 분석하여 소비자의 효율성을 파악한 연구가 각국에서 이루어져 왔으나, 패션제품에 관한 가격과 객관적 품질과의 관계에 관한 연구는 국내 외적으로 매우 미흡한 실정이다. 따라서 본 연구의 목적은 1990년대 한국과 미국 패션시장의 가격과 객관적 품질간의 상관관계를 비교 분석함으로써 양국 패션제품의 품질수준을 비교해 보 는데 있다. 본 연구의 결과를 통해 가격이 제품품질의 지표가 될 수 있는가를 파악할 수 있을 것이다. 이를 위해 본 연구에서는 다음과 같은 연구문제를 설정하였다. 첫째, 한국과 미국 패션제품 시장의 가격과 품질의 상관관계는 전체적으로 어떠한 차이가 있는가\ulcorner 둘째, 한국과 미국 패션제품의 가격과 객관 적 품질의 상관관계가 패션산업범주에 따라 어떠한 차이가 있는가\ulcorner 마지막으로, 본 연구의 결과와 같은 제품의 품질에 대한 정보탐색으로부터 얻을 수 있는 한국과 미국 소비자의 구매이득은 어느 정도인가\ulcorner 본 연구를 위한 내용분석에 이용된 자료는 양국의 소비자의 권익보호를 위한 중립적 정보원에서 발간하고 있는, 한국의 <소비자 시대>와 미국의 에 개 재 된 1990년부터 1999년까지 의 상품비교테스트 정보중에서 패션제품군에 관련된 자료를 토대로 하였다. 수집된 자료는 한국의 36개 패션제품군, 470개 제품과, 미국의 40개 패션제품군. 692개의 패션 제품이었으며, 패션산업범주는 여성복, 남성복, 유니 섹스 의류, 스포츠 의류, 유.아동복, 언더웨어. 잡화. 제화류, 침장류, 섬유직물, 화장품. 학생복 등 11 가지 산업범주로 분류하였다. 본 연구의 결과를 요약하면 다음과 같다. 첫째, 한국과 미국 패션제품의 지난 십년간의 가격 과 품질의 상관관계는 매우 약한 정(+)의 상관을 가지고 있었다. 한국패션제품의 전체 서열상관계수의 평균은 0.091이었고, 미국의 상관계수 평균은 0.192였 다. 상관계수의 수치만으로 볼 때 한국보다는 미국 패션제품의 가격과 품질간의 상관관계가 조금 높게 나타났으나, 양국간 통계적인 차이는 없었다. 또한, 한국 패션제품의 경우에는 제품군의 가격대별 상관관계를 살펴보았는데, 그 결과 1만원 미만의 저가 제품군과 330만원이상의 고가의 제품군의 경우 부(-)의 상관계수를 나타냈다. 둘째. 1990년대 한국과 미국 패션시장의 가격과 품질간의 상관계수의 범위는 제품군별. 산업범주별 로 상이한 분포를 보이고 있었다. 패션제품군별로 보 면, 한국의 경우는 가장 높은 '여행용가방(r = 0.707)' 에서 가장 낮은 '자외선 차단화장품(r = -0.58)'까지, 그리고 미국 패션제품군의 상관계수의 범위는 '팬티 스타킹'의 0.820에서 '남성용 런닝슈즈'의 -0.472까지의 분포를 나타냈다. 마지막으로, 제품의 가격과 품질에 대한 정보를 소비자가 알 경우 얻을 수 있는 소비자의 구매이득 을 추산한 결과 패션제품시장에서 완전한 품질정보를 가지고 있다고 가정한 '현명한 사람'은, 최고가격의 제품만을 구입한다고 가정한 '부유한 사람들'의 구입방식에 비해 최고 좋은 품질의 상품을 총 지불액의 비율로 보아, 한국의 소비자는 약 50% 정도를, 미국의 소비자는 약 91%나 되는 액수를 절약하여 구매할 수 있는 것으로 나타났다. 이상의 본 연구의 결과를 종합하여 볼 때 한국과 미국 모두 제품군별, 그리고 산업범주별로 상관관계가 차이를 보이고 있어, 양국의 소비자들이 패션제품 의 품질을 평가함에 있어 오로지 가격에 대한 정보만을 이용하는 것은 위험하고 비합리적인 구매의사 결정이라고 볼 수 있다. 따라서 소비자가 좀 더 합리적인 구매의사결정을 하여 재정적 손실을 막기 위해서는 가격과 품질에 관한 신뢰있는 정보의 탐색이 반드시 필요하다고 본다.

• Applied Chemistry for Engineering
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• v.31 no.3
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• pp.291-298
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• 2020

ZITO/Ag/ZITO multilayer transparent electrodes at room temperature on glass substrates were prepared using RF/DC magnetron sputtering. Transparent conductive films with a sheet resistance of 9.4 Ω/㎡ and a transmittance of 83.2% at 550 nm were obtained for the multilayer structure comprising ZITO/Ag/ZITO (100/8/42 nm). The sheet resistance and transmittance of ZITO/Ag/ZITO multilayer films meant that they would be highly applicable for use in polymer-dispersed liquid crystal (PDLC)-based smart windows due to the ability to effectively block infrared rays (heat rays) and thereby act as an energy-saving smart glass. Effects of the thickness of the PDLC layer and the intensity of ultraviolet light (UV) on electro-optical properties, photopolymerization kinetics, and morphologies of difunctional urethane acrylate-based PDLC systems were investigated using new transparent conducting electrodes. A PDLC cell photo-cured using UV at an intensity of 2.0 mW/c㎡ with a 15 ㎛-thick PDLC layer showed outstanding off-state opacity, good on-state transmittance, and favorable driving voltage. Also, the PDLC-based smart window optimized in this study formed liquid crystal droplets with a favorable microstructure, having an average size range of 2~5 ㎛ for scattering light efficiently, which could contribute to its superior final performance.

• Applied Chemistry for Engineering
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• v.33 no.1
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• pp.50-57
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• 2022

Ti-In-Zn-O (TIZO)/Ag/TIZO multilayer transparent electrodes were prepared on glass substrates at room temperature using RF/DC magnetron sputtering. Obtained multilayer structure comprising TIZO/Ag/TIZO (10 nm/10 nm/40 nm) with the total thickness of 60 nm showed a transmittance of 86.5% at 650 nm and a sheet resistance of 8.1 Ω/□. The multilayer films were expected to be applicable for use in energy-saving smart window based on polymer-dispersed liquid crystal (PDLC) because of their transmittance properties to effectively block infrared rays (heat rays). We investigated the effects of the content ratio of prepolymer, the thickness of the PDLC coating layer, and the ultraviolet (UV) light intensity on electro-optical properties, and the surface morphology of polyester acrylate-based PDLC systems using new TIZO/Ag/TIZO transparent conducting electrodes. A PDLC cell with a thickness of 15 ㎛ PDLC layer photocured at an UV intensity of 1.5 mW/cm² exhibited good driving voltage, favorable on-state transmittance, and excellent off-haze. The LC droplets formed on the surface of the polymer matrix of the PDLC composite had a size range of 1 to 3 ㎛ capable of efficiently scattering incident light. Also, the PDLC-based smart window manufactured using TIZO/Ag/TIZO multi-layered transparent electrodes in this study exhibited a light brown, which will have an advantage in terms of aesthetics.

• Journal of Bio-Environment Control
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• v.18 no.4
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• pp.332-340
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• 2009

In this study, the thermal insulation effectiveness of the greenhouse insulators by the installation methods was investigated to find the right installation way of the insulation materials. Physical properties of the insulators such as thickness, air transmissivity, apparent density, ultraviolet rays cutoff ratio, reflectance, thermal conductivity, moisture absorptivity were evaluated and the insulation ability of the insulators were measured by the module experiments. For the same insulator, the insulation ability of the case with the outward direction of the black colored face, i.e., with the inward direction of the white colored face, was better than that of vice versa. The case of the black colored both surfaces was better than the case of the white colored both surfaces. For aluminium reflection material, the case with the outward direction of the lustre face, i.e., with the inward direction of the non-lustre face, was better than that of vice versa. For the same material with the inner thin polyethylene foam (or polyester) and the chemical wool, the case with the outward direction of the inner thin polyethylene foam (or polyester), i.e., with the inward chemical wool, was better than that of vice versa. Addition of the inner thin polyethylene foam increased the insulation effect very much.